Injector

ABSTRACT

Injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine is constructed more simple and compact and with a greater durability in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber.

Brenkink Aug. 13, 1974 HNJECTOR Primary ExaminerLaurence M. Goodridge Assistant ExaminerCort Flint [75] Inventor' fiz gggfg Enschede Attorney, Agent, or Firm-Snyder, Brown and Ramik [73] Assignee: Holec N. V., Hengelo, Netherlands [57] ABSCT [22] Filed: Apr. 3, 1972 Appl. No.: 240,470

Injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine is constructed more simple and compact and with a greater durability in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber.

19 Claims, 3 Drawing Figures PAIENTEU 31974 SHEEI 1 01'' 3 1 minutes The invention relates to an injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump having a displacing volume adjustable by means of control means, said pump chamber communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the conbustion engine.

Such an injector is known from the German Pat. specification No. 892,697. In this known injector the displacing bodyof a separate motor is coupled by means of a rod system with the displacing body of a separate fuel pump. Said displacing bodies each consist of a membrane, which is supported directly by the rod system at its one side for only a part of its surface. The part of the membrane which is not supported, is heavily loaded owing to a considerable pressure difference between a fluid and the atmosphere, resulting in a short life of each mentioned membrane and thus of the injectOI'.

The invention provides an injector of the above mentioned kind, which is compact and simple in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber. In this injector only one membrane is provided between each motor and the belonging pump, which is one membrane and one rod system less with respect to the known injector. Each motor adjoins to its belonging pump without an intermediate connection of a rod system, as a result of which the injector according to the invention can be compactly built.

The control means for adjusting the displacing volume of the pump preferably comprise an adjustable stop for the membrane which is mounted in the motor chamber, while a fixed stop for the membrane is mounted in the pump chamber. In this injector the membrane strikes at the end of its pressure stroke against the fixed stop which can support the membrane then each time uniformly, so that the membrane can resist then even'the high combustion pressure of the combustion engine and the durability of the membrane and thus of the injector is long. This durability can yet be lenthened by making the membrane of rubber reinforced with canvas.

The invention will be elucidated in the following description with reference to a drawing.

In the drawing schematically represent:

' FIG. 1 a preferred embodiment of a four stroke combustion engine according to the invention,

FIG. 2 a scheme of the combustion engine of FIG. I

' with details of the injector according to the invention,

and

FIG. 3 a two stroke combustion engine according to the invention.

The six cylinder four stroke combustion engine of FIGS. 1 and 2 comprises a cylinder block 1 with the cylinders 2a, 2b, 2c, 2d, 22 and 2f. The ignition takes successively place in the cylinders 2a, 2e, 20, 2f, 2b and 2d just as in the conventional six cylinder four stroke combustion engine during each two revolutions. The

cylinder 2a is provided with the conventional parts such as ignition plug 4a, inlet valve 5a, exhaust valve 6a, piston 7a, driving rod 8a, crank 9a of a crank shaft 9 and of an air inlet branch 10a of an air inlet manifold 10. According to the invention a fuel pump 3a of an injector 3 is provided for the cylinder 2a. The other cylinders 2b 2f are provided with corresponding parts and fuel pumps 3b 3f respectively.

This combustion engine further comprises a fuel tank 11 for receiving fuel, particularly petrol, and a main petrol pump 12 connected to the fuel tank 11, said pump 12 delivering fuel, e.g. under a pressure of 0,5 ato, to a fuel supply 13 of the injector 3. The fuel pump 3a shown in FIG. 2 delivering fuel to a fuel inlet 14a of the cylinder 2a, comprises a displacing body 15a constituted by a membrane, which adjoins a pump chamber 16a and a motor chamber 17a. The pump chamber 7 16a consists of a compartment 18a, wherein a stop disc 19a is mounted, said disc 19a having axial channels 20a and radial channels 21a, a connecting compartment 22a and a valve compartment 23a. The valve compartment 23a communicates with the fuel supply 13 via an inlet valve 24a while having an initial pressure of 0,6 ato realized by a spring 25a and communicates with a fuel discharge 37a via an exhaust valve 27a while having an initial pressure of 1,5 ato realized by a spring 26a, said fuel discharge 37a communicating in its turn via conduit 28a with the fuel inlet 14a constituted as a sprayer. The fuel inlet 14a sprays fuel into the air inlet branch 10a. A stop 29a axially adjustable in the cylindrical motor chamber 17a, in that said stop 29a is provided with a screwed part 30a, which cooperates with screw thread 31a. The stop 290 comprises at its outside a sealing ring 32a and is connected there to a lever arm 33a which forms the control means for adjusting the displacing volume of the pump chamber 16a. The motor chamber 17a comprises a connection 340, by means of which connection the engine chamber is connected via a narrow conduit 35a to a space of the combustion engine and that to the combustion chamber 36b of cylinder 2b. The fuel pumps 3b, 3c, 3d, 32 and 3f are identically constructed and connected with the understanding that the connections 34b, 34c, 34d, 34e and 34]" respectively are connected to the combustion chambers 36c, 36a, 36f, 36d and 36a respectively. This connection is such that the motor chamber 17a comes under the combustion pressure of a cylinder 2 b while a fuel air mixture is let in into the cylinder 20.

In order to prevent that the fuel pump 3a is heated too strongly the conduit 35a extends partly in the inlet manifold 10 and said conduit 35a is narrowly dimensioned. The membrane 15a is taken up sealingly between the pump halves 38a and 39a being connected to each other. The thin membrane 15a is made of rubber reinforced with canvas. The membrane is not overloaded, in that it is supported by the stops 29a and 19a over a large surface in the end positions and especially in that the fixed ring plane 71 is flush with the fixed from plane 72 of the disc 19a, the outer edge 73 of membrane 15a adjoining said fixed ring plane 71 and the membrane 15a adjoining said disc 19a in untensioned condition under influence of a combustion pressure of eg 20 ato from cylinder 2b.' For exactly and equally adjusting the displacing volume of the pump chambers 16a -l6f all fuel pumps 3a 3f are provided with an identical screw thread and the lever arms 33a 33f are coupled with a common control rod 40 coupled via a joint lever 41 with the throttle pedal 42 of a motor car. An arm 45 of an air valve 44 mounted in the manifold is coupled via a coupled rod 43 with the joint lever 41, so that the quantity of air supplied and the quantity of fuel injected are controlled in the same sense and at the same time by means of the throttle pedal 42.

The one cylinder two stroke combustion engine of FIG. 3 comprises a conventional cylinder block 46 having a motor case 47, a cylinder 48, a piston 49, a driving rod 50, a crank shaft 51, an ignition plug 52, a motor case inlet 53, a by-pass conduit 54 and an exhaust 55. The fuel is sprayed into the motor case 47 by a sprayer 56 which constitutes the fuel inlet and which is fed by the fuel pump 57. This fuel pump 57 is identical with the fuel pump 3b shown in FIG. 2. Its engine chamber comprises a connection 58 which is connected via a conduit 59 to the combustion chamber 60 of the combustion engine. The fuel supply 61 is connected via a fuel conduit 62 to the petrol tank 63. The fuel pump 57 comprises a fuel discharge 64 which communicates via a conduit 65 with the sprayer 56.

The fuel pump 57 comprises a lever 66 which is coupled just as the arm 69 of the air valve 70 via a common controlling rod 67 with a gas handle 68, e.g. of a motor cycle.

What we claim is:

l. lnjector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump having a displacing volume adjustable by means of control means, said pump chamber communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine, characterized in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber, the control means for adjusting the displacing volume of the pump comprising an adjustable stop for the membrane, which is mounted in the motor chamber, while a fixed stop for the membrane is mounted in the pump chamber.

2. Injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump having a displacing volume adjustable by means of control means, said pump chamber communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine, characterized in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber, the membrane being made of rubber reinforced with canvas.

3. In an internal combustion engine having an expandable combustion chamber for burning air-fuel mixture and a further chamber which produces pressure pulses in timed relation with operation of said combustion chamber, a fuel injection system for delivering metered quantities of fuel for said combustion chamber, said system comprising, in combination:

a fuel pump having a fuel delivery chamber for delivering fuel for said combustion chamber and having a motor chamber; fuel-displacing membrane means separating said fuel delivery chamber from said motor chamber for flexed displacement between a predelivery position and a postdelivery position; fuel supply means connected to said fuel delivery chamber for maintaining such chamber full of fuel;

first stop means on the fuel delivery side of said membrane means for engaging the major area of the fuel delivery side thereof to define precisely said postdelivery position of the membrane means;

second stop means on the motor chamber side of said membrane means for engaging the major area of such motor chamber side thereof to define precisely said predelivery position of the membrane means;

pressure pulsing means connecting said motor chamber to said further chamber of the engine for periodically displacing said membrane means from said predelivery position to said postdelivery position thereof; and

means for varying the spacing between said first stop means and said second stop means to control the quantity of fuel metered for said combustion chamber.

4. In an internal combustion engine as defined in claim 3 wherein said fuel supply means comprises a fuel pump and a check valve admitting fuel under pressure to said fuel delivery chamber and wherein the fuel delivery chamber is provided with an outlet check valve allowing discharge of fuel at a pressure higher than that at which fuel is admitted to the fuel delivery chamber.

5. In an internal combustion engine as defined in claim 4 wherein said fuel-displacing membrane means consists of a single, flexible membrane acted upon only by pressure differentials existing between said fuel delivery chamber and said motor chamber.

6. in an internal combustion engine as defined in claim 5 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.

7. In an internal combustion engine as defined in.

claim 3 wherein said engine includes at least two combustion chambers each having a separate fuel injection system, said pressure pulsing means of the fuel injection system for one combustion chamber being connected to the other combustion chamber and vice versa.

8. In an internal combustion engine as defined in claim 3 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.

9. In an internal combustion engine as defined in claim 4 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.

10. In an internal combustion engine as defined in claim 4 wherein said engine includes at least two combustion chambers each having a separate fuel injection 12. A fuel injection system for internal combustion engines comprising, in combination:

a fuel injector pump having a fuel delivery chamber and a motor chamber;

a fuel-displacing membrane separating said fuel delivery chamber from said motor chamber, said 7 membrane having at least a marginal portion which is freely flexible whereby to allow said membrane to flutter back and forth under the influence of pressure differentials between said fuel delivery chamber and said motor chamber;

first stop means disposed on the fuel delivery chamber side of said membrane for arresting said membrane in fixed, postdelivery position;

second stop means disposed on the motor chamber side of said membrane for arresting said membrane in fixed, predelivery position;

means for selectively varying the spacing between said first stop means and said second stop means correspondingly to vary the volume swept by said membrane in moving from its predelivery position to its postdelivery position;

fuel inlet means connected to said fuel delivery chamber for one way delivery of fuel to said fuel delivery chamber at a first selected pressure;

fuel outlet means connected to said fuel delivery chamber for one way discharge of fuel from said fuel delivery chamber in response to a second was sure greater than said first selected pressure whereby fuel continuously occupies said fuel delivery chamber at a pressure which at least is said first selected pressure;

membrane displacing pressure means connected to said motor chamber for subjecting said motor chamber alternately to a pressure greater than said second pressure and a pressure less than said first pressure whereby said membrane is displaced to its predelivery position when the motor chamber pressure is less than said first pressure and is displaced to its postdelivery position when the motor chamber pressure is greater than said second pressure; said membrane displacing pressure means including conduit means adapted for connection to a chamber of an associated internal combustion engine which produces pressure pulses at the firing frequency of a combustion chamber of such engme.

13. A fuel injection system as defined in claim 12 wherein said membrane presents opposite side surfaces exposed respectively to said fuel delivery chamber and said motor chamber, said first stop means having an es sentially flat surface which engages the major area of that side of the membrane facing said fuel delivery chamber when the membrane is in its postdelivery position and said second stop means likewise having an essentially flat surface which engages the major area of that side of the membrane facing said motor chamber when the membrane is in its predelivery position.

14. A fuel injection system as defined in claim 13 wherein said membrane is subjected only to the influence of said pressure differentials whereby the fueldisplacing effect of the system is characterized by low inertia capable of responding to high speed operation of an associated internal combustion engine.

15 A fuel injection system as defined in claim 12 wherein said membrane is subjected only to the influence of said pressure differentials whereby the fueldisplacing effect of the system is characterized by low inertia capable of responding to high speed operation of an associated internal combustion engine.

16. An internal combustion engine-fuel injector systern comprising, in combination:

an internal combustion engine having an expansion chamber adapted periodically to burn fuel-air mixture;

an injector pump having a fuel delivery chamber and a motor chamber; said injector pump including:

a membrane separating said fuel delivery chamber from said motor chamber and flexibly connected marginally thereof to said pump so as to be free to flutter back and forth between predelivery and post delivery positions;

conduit means connected to said fuel delivery chamber for discharging fuel therefrom to the engine when the fuel pressure in said fuel delivery chamber reaches a predetermined value;

membrane displacingmeans for fluttering said membrane between its predelivery and postdelivery positions; said membrane displacing means compising check valve means connected to said fuel delivery chamber for admitting fuel to such fuel delivery chamber at a first pressure less than said predetermined value at which fuel is discharged from said chamber and fuel supply means for supplying pressurized fuel to said check valve means at said first pressure, and'pressuring means connected to said engine for alternately subjecting said motor chamber to pressure greater than said predetermined value and less than said first pressure and at a frequency equal to the operating frequency of said expansion chamber;

stop means disposed on opposite sides of said membrane for fixing the extreme positions to which said membrane may be fluttered by said membrane displacing means; and

means for selectively adjusting said stop means to increase and to decrease the volume swept by said membrane in moving between its extreme positions.

17. An internal combustion engine-fuel injection system as defined in claim 16 wherein said engine includes a second expansion chamber and a second injector pump associated therewith.

18. An internal combustion engine-fuel injection system as defined in claim 17 wherein the pressuring means of the injector pump first mentioned connects the motor chamber of said first pump to said second expansion chamber and vice versa.

19. in an internal combustion engine having plural chambers for successively inducting air-fuel mixture charges and having a separate fuel injector for each of such plural chambers, each such fuel injector comprismg:

an injector pump having a fuel delivery chamber and a motor chamber, and a flexible membrane separating such fuel delivery chamber and such motor chamber which is free to flutter between two extreme positions;

fuel supply means connected to said fuel delivery chamber and including a check valve for admitting fuel at a first selected pressure to said fuel delivery chamber whereby to pressurize one side of said membrane at said first selected pressure;

fuel outlet means connected to said fuel delivery chamber and including a check valve for delivering a metered quantity of fuel at a second selected pressure to form the fuel component of the air-fuel charge of an associated one of said plural chambers of the engine, said second selected pressure being greater than said first selected pressure;

pressure pulse means connecting said motor chamber to said engine for pressure pulsing said motor chamber in synchronism with the air-fuel mixture charge induction of said associated engine chamber, said pressure pulse means effecting transient pressure in said motor chamber which is greater than said second selected pressure followed by second transient pressure in said motor chamber which is less than said first selected pressure, whereby to cause reversal of pressure differential across said membrane and consequent fluttering thereof between its extreme positions; and

stop means located on opposite sides of said membrane for physically engaging the membrane and positively fixing the extreme positions thereof to establish a precise volume swept by the membrane in moving between such extreme positions, said stop means including means for selectively varying said precise volume swept to control the metered quantity of fuel which forms said fuel component of the air-fuel charge inducted by the associated v v v UNiTEI) STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3"8Z8'748 Dated G-1 1113, 1974 Inven Bernard .Breukink It is certified that error appears in the above-identified patent and that said Letters Patentare hereby corrected as shown below:

[30] Foreign Application Priority Data April 5, 1971 Netherlands 71.04559 Signed and sealed this 24th day of December 1974.

(SEAL) Attest:

McCOY M. GIBSON JR. c. MARSHALL DANN AttestingQffi cer, Comissioner-of Patents -0RM PC7-1050 v I I i uscoMM-oc 60376-P69 v i ".5. GOVERNMENT PRINTING OFFIC! I 5" 0"365'334, 

1. Injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump having a displacing volume adjustable by means of control means, said pump chamber communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine, characterized in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber, the control means for adjusting the displacing volume of the pump comprising an adjustable stop for the membrane, which is mounted in the motor chamber, while a fixed stop for the membrane is mounted in the pump chamber.
 2. Injector for delivering fuel to at least one fuel inlet of a combustion engine, the pump chamber of at least one fuel pump having a displacing volume adjustable by means of control means, said pump chamber communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to the fuel inlet of the combustion engine and said pump chamber being adjoined by at least one membrane, wherein a motor chamber for driving the fuel pump comprises a connection for connecting said motor chamber to a space of the combustion engine, said space having a pressure fluctuating per combustion cycle of the combustion engine, characterized in that one and the same membrane adjoins at its one side the pump chamber and at its other side the motor chamber, the membrane being made of rubber reinforced with canvas.
 3. In an internal combustion engine having an expandable combustion chamber for burning air-fuel miXture and a further chamber which produces pressure pulses in timed relation with operation of said combustion chamber, a fuel injection system for delivering metered quantities of fuel for said combustion chamber, said system comprising, in combination: a fuel pump having a fuel delivery chamber for delivering fuel for said combustion chamber and having a motor chamber; fuel-displacing membrane means separating said fuel delivery chamber from said motor chamber for flexed displacement between a predelivery position and a postdelivery position; fuel supply means connected to said fuel delivery chamber for maintaining such chamber full of fuel; first stop means on the fuel delivery side of said membrane means for engaging the major area of the fuel delivery side thereof to define precisely said postdelivery position of the membrane means; second stop means on the motor chamber side of said membrane means for engaging the major area of such motor chamber side thereof to define precisely said predelivery position of the membrane means; pressure pulsing means connecting said motor chamber to said further chamber of the engine for periodically displacing said membrane means from said predelivery position to said postdelivery position thereof; and means for varying the spacing between said first stop means and said second stop means to control the quantity of fuel metered for said combustion chamber.
 4. In an internal combustion engine as defined in claim 3 wherein said fuel supply means comprises a fuel pump and a check valve admitting fuel under pressure to said fuel delivery chamber and wherein the fuel delivery chamber is provided with an outlet check valve allowing discharge of fuel at a pressure higher than that at which fuel is admitted to the fuel delivery chamber.
 5. In an internal combustion engine as defined in claim 4 wherein said fuel-displacing membrane means consists of a single, flexible membrane acted upon only by pressure differentials existing between said fuel delivery chamber and said motor chamber.
 6. In an internal combustion engine as defined in claim 5 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.
 7. In an internal combustion engine as defined in claim 3 wherein said engine includes at least two combustion chambers each having a separate fuel injection system, said pressure pulsing means of the fuel injection system for one combustion chamber being connected to the other combustion chamber and vice versa.
 8. In an internal combustion engine as defined in claim 3 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.
 9. In an internal combustion engine as defined in claim 4 wherein said engine includes at least two combustion chambers each having a separate fuel injection system.
 10. In an internal combustion engine as defined in claim 4 wherein said engine includes at least two combustion chambers each having a separate fuel injection system, said pressure pulsing means of the fuel injection system for one combustion chamber being connected to the other combustion chamber and vice versa.
 11. In an internal combustion engine as defined in claim 5 wherein said engine includes at least two combustion chambers each having a separate fuel injection system, said pressure pulsing means of the fuel injection system for one combustion chamber being connected to the other combustion chamber and vice versa.
 12. A fuel injection system for internal combustion engines comprising, in combination: a fuel injector pump having a fuel delivery chamber and a motor chamber; a fuel-displacing membrane separating said fuel delivery chamber from said motor chamber, said membrane having at least a marginal portion which is freely flexible whereby to allow said membrane to flutter back and forth under the influence of pressure differentials between said fuel delivery chamber and said motor chamber; first stop means disposed on the fuel delivery chamber side of said membrane for arresting said membrane in fixed, postdelivery position; second stop means disposed on the motor chamber side of said membrane for arresting said membrane in fixed, predelivery position; means for selectively varying the spacing between said first stop means and said second stop means correspondingly to vary the volume swept by said membrane in moving from its predelivery position to its postdelivery position; fuel inlet means connected to said fuel delivery chamber for one way delivery of fuel to said fuel delivery chamber at a first selected pressure; fuel outlet means connected to said fuel delivery chamber for one way discharge of fuel from said fuel delivery chamber in response to a second pressure greater than said first selected pressure whereby fuel continuously occupies said fuel delivery chamber at a pressure which at least is said first selected pressure; membrane displacing pressure means connected to said motor chamber for subjecting said motor chamber alternately to a pressure greater than said second pressure and a pressure less than said first pressure whereby said membrane is displaced to its predelivery position when the motor chamber pressure is less than said first pressure and is displaced to its postdelivery position when the motor chamber pressure is greater than said second pressure; said membrane displacing pressure means including conduit means adapted for connection to a chamber of an associated internal combustion engine which produces pressure pulses at the firing frequency of a combustion chamber of such engine.
 13. A fuel injection system as defined in claim 12 wherein said membrane presents opposite side surfaces exposed respectively to said fuel delivery chamber and said motor chamber, said first stop means having an essentially flat surface which engages the major area of that side of the membrane facing said fuel delivery chamber when the membrane is in its postdelivery position and said second stop means likewise having an essentially flat surface which engages the major area of that side of the membrane facing said motor chamber when the membrane is in its predelivery position.
 14. A fuel injection system as defined in claim 13 wherein said membrane is subjected only to the influence of said pressure differentials whereby the fuel-displacing effect of the system is characterized by low inertia capable of responding to high speed operation of an associated internal combustion engine.
 15. A fuel injection system as defined in claim 12 wherein said membrane is subjected only to the influence of said pressure differentials whereby the fuel-displacing effect of the system is characterized by low inertia capable of responding to high speed operation of an associated internal combustion engine.
 16. An internal combustion engine-fuel injector system comprising, in combination: an internal combustion engine having an expansion chamber adapted periodically to burn fuel-air mixture; an injector pump having a fuel delivery chamber and a motor chamber; said injector pump including: a membrane separating said fuel delivery chamber from said motor chamber and flexibly connected marginally thereof to said pump so as to be free to flutter back and forth between predelivery and post delivery positions; conduit means connected to said fuel delivery chamber for discharging fuel therefrom to the engine when the fuel pressure in said fuel delivery chamber reaches a predetermined value; membrane displacing means for fluttering said membrane between its predelivery and postdelivery positions; said membrane displacing means compising check valve means connected to said fuel delivery chamber for admitting fuel to such fuel delivery chamber at a first pressure less than said predetermined value at which fuel is discharged from said chamber and fuel supply means for supplying pressurized fuel to said check valve means at said first pressure, and pressuring means connected to said engine for alternately subjecting said motor chamber to pressure greater than said predetermined value and less than said first pressure and at a frequency equal to the operating frequency of said expansion chamber; stop means disposed on opposite sides of said membrane for fixing the extreme positions to which said membrane may be fluttered by said membrane displacing means; and means for selectively adjusting said stop means to increase and to decrease the volume swept by said membrane in moving between its extreme positions.
 17. An internal combustion engine-fuel injection system as defined in claim 16 wherein said engine includes a second expansion chamber and a second injector pump associated therewith.
 18. An internal combustion engine-fuel injection system as defined in claim 17 wherein the pressuring means of the injector pump first mentioned connects the motor chamber of said first pump to said second expansion chamber and vice versa.
 19. In an internal combustion engine having plural chambers for successively inducting air-fuel mixture charges and having a separate fuel injector for each of such plural chambers, each such fuel injector comprising: an injector pump having a fuel delivery chamber and a motor chamber, and a flexible membrane separating such fuel delivery chamber and such motor chamber which is free to flutter between two extreme positions; fuel supply means connected to said fuel delivery chamber and including a check valve for admitting fuel at a first selected pressure to said fuel delivery chamber whereby to pressurize one side of said membrane at said first selected pressure; fuel outlet means connected to said fuel delivery chamber and including a check valve for delivering a metered quantity of fuel at a second selected pressure to form the fuel component of the air-fuel charge of an associated one of said plural chambers of the engine, said second selected pressure being greater than said first selected pressure; pressure pulse means connecting said motor chamber to said engine for pressure pulsing said motor chamber in synchronism with the air-fuel mixture charge induction of said associated engine chamber, said pressure pulse means effecting transient pressure in said motor chamber which is greater than said second selected pressure followed by second transient pressure in said motor chamber which is less than said first selected pressure, whereby to cause reversal of pressure differential across said membrane and consequent fluttering thereof between its extreme positions; and stop means located on opposite sides of said membrane for physically engaging the membrane and positively fixing the extreme positions thereof to establish a precise volume swept by the membrane in moving between such extreme positions, said stop means including means for selectively varying said precise volume swept to control the metered quantity of fuel which forms said fuel component of the air-fuel charge inducted by the associated engine chamber. 